Thermal rating method of delivery wind-power transmission line

Abstract

The invention discloses a thermal rating method of a delivery wind-power transmission line. On the basis of a relation of a transmission line lead temperature, a service life, and a sag, an optimal decision model of a transmission line thermal rating value is constructed by using a total fan suspending power caused by transmission line thermal rating value limiting within the expected service life of the transmission line as an objective function and using the conductor thermal balance, transmission line tensile strength loss, and security margin restriction as constraints; current carrying values of the transmission line during all periods are calculated; comparison of the current carrying values with an initial thermal rating value is carried out; if the current carrying values are larger than the initial thermal rating value, fan suspending powers in the objective function during the period are calculated and are accumulated; the conductor temperature and the tensile strength loss of the transmission line are updated; and iteration and repetition are carried out continuously until the time objective function of the expected service life of the transmission line becomes zero and then a to-be-decided content is solved. According to the invention, on the basis of the service life of the transmission line and the security margin demand, the conductor tensile strength loss and sag constraints are constructed, thereby effectively eliminating conservatism of the traditional thermal rating method and effectively enhancing the wind-power receiving capability of the power grid.

Description

technical field [0001] The invention relates to a thermal setting method for an external wind power transmission line. Background technique [0002] In recent years, wind power has developed rapidly due to the advantages of wide distribution of resources, mature technology, and short construction period. The construction of power grids is relatively slow, and insufficient transmission capacity has become one of the important factors restricting the acceptance of wind power in the power grid. [0003] Thermal limitation is the essence of the load capacity of transmission components. The industry standards of various countries have given the reference value of the maximum permissible temperature (Maximum Permissible Temperature, MPT) for long-term continuous operation of transmission lines (ACSR) as the basis for calculation of thermal values ​​(such as my country's MPT reference value is 70°C, France is 85°C, Japan is 90°C, etc.). On the basis of a given MPT, the Static Therm...

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Problems solved by technology

[0008] The current-carrying and temperature of the transmission lines for sending wind power to the outside have strong fluctuations, which makes the accumulation process of the conductor tensile strength loss also fluctuating. In order to highlight, if the relationship between the temperature of the transmission line conductor and the loss of tensile strength can be directly considered, and the sag limit of the transmission line operation can be taken into account, the calculation of the thermal value that can meet the requirements of the safe clearance distance and service life of the transmission line must be realized. It can improve the conservatism of traditional thermal ratings and enhance the ability of the grid to accept wind power

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